PaxVax announced that it has commenced its Phase 3 clinical trial program for its single-dose oral cholera vaccine candidate, PXVX0200 (also known as CVD 103-HgR). Approximately 3,000 participants will be enrolled in this pivotal program, which is comprised of cholera challenge, safety, and immunogenicity studies. PaxVax said that “a cholera vaccine is available in Europe and elsewhere for travelers, but it requires a two-dose regimen, which takes longer to complete. A single-dose, oral vaccine would be more convenient for all travelers to take, particularly for those traveling on short notice.” The pivotal efficacy cholera challenge studies will be randomized, double-blind, placebo-controlled, and conducted at three top vaccine testing centers, including the University of Maryland, the University of Vermont Vaccine Testing Center, and Cincinnati Children’s Hospital Medical Center. Volunteers enrolled in these studies will first be vaccinated and then challenged, or exposed to the cholera-causing agent (Vibrio cholerae bacterium). At 10 days following vaccination, and again at three months post vaccination, participants will be evaluated to determine the protective ability of PXVX0200. All standard clinical trial safety protocols and guidelines will be followed at each clinical research center. Additional trials will also be conducted at sites in Canada, Australia, and the U.S. to confirm vaccine safety in a larger population, measure immunogenicity, and demonstrate lot-to-lot consistency of different vaccine manufacturing batches required by the U.S. Food and Drug Administration (FDA). In recognition of the lack of any available traveler’s vaccine against cholera, and the corresponding unmet medical need, PXVX0200 has been granted Fast Track designation by FDA.